Ahydrologist from a government agency tests several samples of water for safety. as part of his examinations, he determines the concentration of lead that is present in each sample. which method of expressing concentration should the hydrologist use to describe the concentration of lead in the water?

Alexander calder's mobiles are an example of motion because it uses forces of wind and water.

An electron and a proton have the same kinetic energy upon entering a region of constant magnetic field and their velocity vectors are perpendicular to the magnetic field. suppose the magnetic field is strong enough to allow the particles to circle in the field. note: you'll need to look up the masses for an electron and proton. 1) what is the ratio of the radii of their circular paths rp/re?

A0.580-kg rock is tied to the end of a string and is swung in a circle with a radius of 0.500 meters. the velocity of the rock is 4.50 m/s. what is the centripetal force acting on the rock? 15.5 n 5.22 n 69.8 n 23.5 n